In a GERAN network, a measurement function and a reselection function of a cell totally relate to the following lists.
1) Broadcast control channel allocation list (Broadcast Control Channel Allocation List, BA list)
Generally, the BA list is merely used for functions of measuring a GERAN cell, reporting the measurement, and cell reselection, and the BA list includes a frequency and frequency index information of a GERAN neighbour cell. The BA list is constructed by an SI2/SI2bis/SI2ter message or an SI5/SI5bis/SI5ter message, or is constructed by PSI3 and PSI3bis when a packet broadcast control channel (Packet Broadcast Control Channel, PBCCH) exists.
2) GSM neighbour cell List (GSM Neighbour Cell list, GSM NCL)
Generally, The GSM NCL is also merely used for the functions of measuring a GERAN cell, reporting the measurement, and cell reselection. The GSM NCL includes a frequency of a GERAN neighbour cell, a base transceiver station identity code (Base transceiver station Identity Code, BSIC) of a GERAN neighbour cell, and cell index information of a GERAN neighbour cell. The GSM NCL is constructed by the BA list and SI2quater or by the BA list and a Measurement Information message, or is constructed by PSI3 and PSI3bis when the PBCCH exists, and at this time, the GSM NCL is the same as the BA list.
3) 3G neighbour cell List (3G Neighbour Cell list, 3G NCL)
Generally, the 3G NCL is used to measure a 3G neighbour cell and report the measurement, and the list includes a frequency of the 3G neighbour cell, scrambling of the 3G neighbour cell, a bandwidth of the 3G neighbour cell, and index information of a 3G cell. The 3G Neighbour Cell list is constructed by an SI2quater message when the PBCCH does not exist, or is constructed by a PI3quater message when the PBCCH exists. The 3G NCL may be modified by a packet measurement order (Packet Measurement Order, PMO) message or a packet cell change order (Packet Cell Change Order, PCCO) message.
4) 3G cell reselection list/GPRS 3G cell reselection list (3G Cell Reselection list/GPRS 3G Cell Reselection list)
The 3G Cell Reselection List/GPRS 3G Cell Reselection List is used for reselection of a 3G neighbour cell, and the list includes a frequency of a 3G cell, scrambling information of the 3G cell and bandwidth information of the 3G cell, or may further include only frequency information other than the foregoing specific cell information. Since in a 3G network, many different cells exist in the same frequency, and the different cells are distinguished according to parameters such as scrambling and a bandwidth, in the case that only the frequency information is given, when cell reselection is performed, any cell in the frequency may be selected. The 3G Cell Reselection list is constructed by the SI2quater message and the SI2ter message. The GPRS 3G Cell Reselection list is constructed by the SI2quater message and the SI2ter message when the PBCCH does not exist, or is constructed by the PSI3quater message when the PBCCH exists.
5) Neighbour cell List (Neighbour Cell list, NCL)
The NCL is generally used in an enhancement-type measurement report, and is used to measure and report all neighbour cells (including the GERAN cell and the 3G cell), and the list includes a frequency and BSIC information of the GERAN cell, a frequency, scrambling and a bandwidth of the 3G cell, and index information of each cell. The NCL is generally formed through a series connection of the GSM NCL and the 3G NCL.
6) E-UTRAN neighbour cell List (E-UTRAN Neighbour Cell list, E-UTRAN NCL)
The E-UTRAN NCL is used for measurement, report and reselection of an E-UTRAN neighbour cell and the list includes a frequency of the E-UTRAN neighbour cell, information about an E-UTRAN neighbour cell that is not allowed to be assessed, and a frequency index of the E-UTRAN neighbour cell. The E-UTRAN NCL is constructed by the SI2quater message or the Measurement Information message or the PSI3quater message, and may be modified by the PMO message or the PCCO message.
In a current measurement report, for the GERAN cell, a frequency index of the BA list and a BSIC value are used to identify one GERAN cell; for a UTRAN cell, a cell index in the 3G NCL is used to identify one UTRAN cell; and for the E-UTRAN NCL cell, the frequency index in the E-UTRAN NCL and physical cell identification (Physical Cell Identification, PCI) are used to identify one cell.
In the prior art, cell information included in the 3G Cell Reselection list is jointly provided by the SI2quater message and the SI2ter message. In the case that the PBCCH does not exist, the GPRS 3G Cell Reselection list is equal to the 3G Cell Reselection list, and in the case that the PBCCH exists, the GPRS 3G Cell Reselection list is provided by the PSI3quater message. Since the 3G Cell Reselection list/GPRS 3G Cell Reselection list is used only in autonomous cell reselection, and the GPRS 3G Cell Reselection list is merely used for a terminal to perform reselection in a network controlled cell reselection mode 0 (Network Controlled cell reselection Mode 0, NC0) and a network controlled cell reselection mode 1 (Network Controlled Mode 1, NC1), a frequency and a cell index are not defined during construction of the list, and during entering a connected mode, since no cell index exists in the GPRS 3G Cell Reselection list, a network side modifies only the 3G Neighbour list through the PMO message or the PCCO message, but does not modify the GPRS 3G Cell Reselection list.
A priority concept is brought into a current standard protocol, and the network side delivers priority information of each RAT in a manner of a 3G cell frequency index, that is, a priority of each frequency is delivered according to a frequency index of each frequency in the 3G. Since no frequency index is established in the 3G Cell Reselection list/GPRS 3G Cell Reselection list, priority information cannot be brought into the 3G Cell Reselection list/GPRS 3G Cell Reselection list. However, the 3G Cell Reselection list/GPRS 3G Cell Reselection list is a list used for cell reselection, and during the cell reselection, because no related priority information exists in the frequency included in the list, the terminal fails to perform the cell reselection that is based on the priority.
In another aspect, generally, the PMO or PCCO modifies only the 3G Neighbour Cell list, but does not modify the 3G Cell Reselection list/GPRS 3G Cell Reselection list. Since the 3G Neighbour Cell list is used for the measurement and report, and the 3G Cell Reselection list/GPRS 3G Cell Reselection list is used for the cell reselection, the network fails to change related information about the cell reselection of the terminal when a 3G frequency is added or deleted through the PMO or the PCCO.